DanSE

iTrader: (1)

Anyone know, just wondering cause I might go to the track tonight and wondering if I should not waste the 6 bucks.
Thanks,
Dan

MAXimumHP

iTrader: (7)

Octane in gas does not make it more powerful, the gas in gas is what makes power. Octane only helps slow the flame propagation to prevent the mixture from igniting prematurely. The Maxima will only advance the timing so far. If it can reach that point on pump gas, octane additives will do nothing but fill combustion camber space that could have been filled with gas. Chances are if you use 93 (if it's available where you are) octane additive will do nothing. If you still get detonation and the ECU retarding the timing on high octane pump gas, octane additive will help. If your car is NA, running good, and not overheating, I don't think it will do much good, but putting it in can't hurt too much either tho.

StygianMax

iTrader: (8)

This timing does not vary right? I read an good article about octane in the Aug or Sept issue of "Modified" & I seem to recall it saying each car is shipped from the factory with a certain timing. Moreover, it does not adjust itself based on the type of gas used.
I have wondered that the optimal octane count is for our engines. Based on the way octane actually works, there should be some maximum octane cout beyond which there are zero gains to be had in the power output from the engine.

maximadave

iTrader: (10)

What about if you engine is stock (stock intake too), use Chevron 91 9 times out of 10, tried octane booster and the engine is still pinging continously on the freeway on a hot day, what can I do next to cure it.....

just look at my SHIFT_ tag line now.....lol

MAXimumHP

iTrader: (7)

I can't speak for all cars, but the Maxima does adjust the spark timing. That's what the knock sensor is for. If it detects detonation, it retards the timing. As I said octane does not make power, only allows an engine to be more highly tuned. The maximum octane rating useful will vary from car to car depending on the engines condition, Environment conditions etc. Although I can agree they will all probably be close. I'm sure when Nissan designed the engine they did not anticipate it ever running more than 95 octane in the US. So I doubt much more than that will do much good.

maximadave,
You should not hear audible detonation on the highway, that is bad. If so, sounds like the ECU is leaning the mixture way to much while in closed loop and your knock sensor is not doing it's job. Have you brought it to a shop yet?

maximadave

iTrader: (10)

Yes, on 4 different occasions. The dealer got in touch with Nissans tech dept and told the dealer, "Have the customer read the owners manual, it states that occasional spark knock is normal and not to worry, it actually helps on gas mileage"

At the same time I put my engine back to stock and it still pings. It doesn't ping at night when its cooler, just during a hot day. The dealer also performed the hesitation TSB and replaced the MAF and did 2 flash ECU upgrades (one came out about a month ago). Nissan recently sent me a survey and gave the dealer good marks (they were up in arms in what to do and accomodated me well) but gave the Nissan tech dept an ear full. I know the service tech and he checked for all the sensors if any that have gone bad and he said everything is working fine. I even asked him about the ignition coils going bad (I had them replaced at 22K miles, car has 43K now) and he said he doesn't see that problem on this car.

Any suggestions? Thanks for your help....

spirilis

iTrader: (2)

maximadave-- You sure there's no air in the cooling system? Odd that it does that only on hot days...
Got an OBD-II scantool with sensor recording?

maximadave

iTrader: (10)

Dont know if there is and I dont have an OBD-II scan tool. I'm going to try again this coming week and take it over to where jdmmax works at Superior Nissan. I'll post the results. Very good possibilty its the knock sensor. It's not throwing a code but could have a short in it like my MAF sensor did

ChromeSE5

iTrader: (3)

In an article in Sport Compact Car, they were fixing up an r34 or r33. Anyways... they couldn't get high octane fuel for thier dyno testing so they added NOS off road formula to thier fulltank of 91 gas. So they dynoed the car before the NOS additive and after. The dyno showed a gain of 10hp. I don't think a maxima will have that type of gain. I know though that an RB26DETT engine (skyline) responds nicely to almost any mod (learned from Sport Compact Car and Gran Turismo 1,2, and 3 )